from rest_framework import serializers

from goods.models import SKU


class CartSerializers(serializers.Serializer):
    sku_id = serializers.IntegerField(min_value=1,label="商品编号")
    count = serializers.IntegerField(min_value=1,max_value=200,label="数量")
    selected = serializers.BooleanField(default=True,required=False)

    #1,多字段校验
    def validate(self, attrs):
        #0,获取数据
        sku_id = attrs["sku_id"]
        count = attrs["count"]

        #1,判断商品是否存在
        try:
            sku = SKU.objects.get(id=sku_id)
        except Exception as e:
            raise serializers.ValidationError("商品不存在")

        #2,判断count是否大于了库存量
        if count > sku.stock:
            raise serializers.ValidationError("库存不足")

        #3,返回
        return attrs

class CartDeleteSerializer(serializers.Serializer):
    sku_id = serializers.IntegerField(min_value=1, label="商品编号")

    #1,单字段校验
    def validate_sku_id(self, sku_id):
        #1,获取sku_id对应的对象是否存在
        try:
            SKU.objects.get(id=sku_id)
        except Exception as e:
            raise serializers.ValidationError("商品不存在")

        #2,返回
        return sku_id